Wings (also fins, stabilizer, nacelles, nose cones etc.) of aircraft comprise airframe leading edges. The leading edge is often made as an one-piece member or multi-piece members, which can be designed to be removable or cut from the wing and exchanged with a new airframe leading edge bonded or bolted to the wing box structure. Such exchange is made if the aircraft has collided with a bird, or in case of ground accidents, wherein the air frame leading edge has been damaged or buckled. Heavy birds could also damage the structure of the wing/fin/stabilizer/nacelle/nose in event of collision. Such collisions may especially occur during takeoff and landing in bird-rich biotopes. In such case the risk of accident is high. The object impacting on the leading edge thus may cause large damage to the adjacent structure. Also flying through hailstorm could negatively affect the leading edge and airframe structure. Also accidental collisions against hangar ports and parked aircraft may occur and it is a desirable to protect the structural portion (wing skin spars, electronics with structural portion etc.) and at the same time in a cost- and time-effective way to exchange the damaged airframe leading edge to a new leading edge.
U.S. Pat. No. 4,657,615 discloses a composite article comprising a leading edge. The leading edge portion and a spar portion are connected together to form a one-piece member. The leading edge is bond to the spar portion by using an adhesive applied between a backside of the leading edge and the spar portion.
Furthermore, WO 2004/098993 discloses a wing having a structural part and a separable complementary leading edge part, which comprises an energy adsorption material core. The purpose of the leading edge in WO 2004/098993 is to provide a wing structure that is able to withstand a strike of a large bird or another object. This is solved by arranging a honeycomb material or foam that absorbs a high amount of energy and distributes the impact span-wise over the wing's leading edge. A backside of the leading edge part constitutes a sheet that forms the edge part to a beam for protection of the structural part. A recess is formed between the structural part's skin shell and the skin shell of the leading edge.
US 2009/0127392 discloses a leading edge having a skin which deforms into a void of the leading edge when a force acts on the skin so as to absorb the force without damaging the structure. The skin of the leading edge is bonded or glued firmly to the wing structure situated behind the leading edge seen in the direction of flight.
The object of the present invention is to develop and improve known technique.
Another object is to provide an airframe leading edge that prevents damage to the aircraft structure as a result of e.g. a bird strike.
Another object is to provide a replaceable airframe leading edge which is light in weight and which is easy to remove and replace.
Also is it an object to protect the structural portion of an aircraft during taxi and roll transports in hangars.